Detinning.



-16, 1904, Serial No. 189,272, we have scribed aprocess'of detinning especially ap- UNITED STATES; PATENT OFFIOE- FRANZ VON KUGE-LGEN AND GEORGE" Of S'EWARD, OF HOLOOMBS :ROOK, VIRGINIA, ASSIGNORS', BY MESNE ASSIGNMENTS, TO TIN PRODUCTS COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent. Application filed August sgl'e'oa. Serial No. 272.453.

Patented. Ma 14, 190?.

States, both residing at Holcombs Rock, inthe county of Bedford and State of Virginia, have jointly invented certain new and; useful Improvements in Detinning, of which the following is a specification.

' In our application for patent filed J anuiary licableto the recovery of tin from tin scrap. aid process, broadly described, consists in treating the tin scrap with dry chlorin gas in closed vessels, thus obtaining liquid stannic chlorid, which mostly collects in the bottom of the vessel and'can be removed by gravity.' It is not, however, all so removed, and a film of it remains adhering to the detinned scrap. It is absolutely necessary to remove this adhering stannic chlorid before the tanks can be opened with safety to the operator, as it produceschoking fumes upon contact with the air; the present invention relates particularly to,-the method of removing such anhydrous stannic chlorid from the detinning tank. This removal is accomplished in the following manner :After the reaction is complete, and. the tin in thetank has all been converted into stannic chlorid, which hasbeen removed as much as possible by gravity from the bottom of the tank, we continue to passdry chlorin through the tank, -which now containsscrap free from metallic tin, but with a certain amount of stannic chlorid adhering ,-to'- it. Chlorin has the capacity of absorbing a and by ava' inggof this property we thus get rid of the remainder of the stannic chloridso that it is taken up by the chlorin and passes I vessel by passing dry air throughit.

chlorin is driven out by a current of air, after invention.

'eat quantity of stannic chlorid,

Which-the tank may be safely opened for the I removal of the detinned scrap. It has been found of advantage to pass the air, used to replace the chlorin, through amass of heated The, 'stannio chlorid and chlorin,

WhlCh are thus'successively removed from.

the tank after'the com letlon of the detinnin are passed into ot er tanks containing ,fres quantities of scrap, and so utilized.

Though we havedescribed with great partioularity of detail certain embodiments of theinvention, yet it will be understood. that modifications thereof may be made by those skilled in the art without departure from the What we claim is .1. bypassing-dry chlorin over tin scrap and after'the d'etinning is complete removing the The process which consists in detinning residual anhydrous stannic chlorid from the detinning vessel through, and fin from the vessel.

2. The process which consists in detinning by subjecting tin scrap to the action of dry chlorin at a temperature below that at which stannic chlorid volatilizes, and subsequently by passing chlorin thereal y expelling the chlorin removing the residual stannic chlorid from the detinning vessel by passing chlorin therethrough. i y 3. The process of removing anhydrous stannic chlorid from a detinning tank, which consists in pasing'chlorinthrough the detinned scrap and replacing the chlorin in turn by air from which theoxy'gen has been removed.

-In witness whereof, we have hereunto signed our names in the presence of two subscribing witnesses. U

FRANZ VON KUGELGEN. GEORGE O. SEVVAHID.

Witnesses:

Gno. T. LANCASTER, FR. v. KIDDER. 

